The invention is particularly described with reference to longitudinally arcuate building elements. Typically building elements of this kind have been used to construct farm buildings, garages and the like of upwardly convexed arched structure comprising a plurality of prefabricated longitudinally arcuate elements that extend continuously from one side foundation of the building to the other arranged side by side with their abutting edges secured together thereby forming a stand alone building devoid of bracing, trusses or other structural reinforcements.
Traditionally the elements have been formed in two or more passes through roll forming apparatus or have required very long roll forming lines. Conventional processes and apparatus generally produce relatively short span elements which for long span buildings have been joined end to end with overlapping edge margins. Consequently, in constructing long span buildings, typically the short span elements are either joined end to end on the ground prior to being hoisted into position alongside previously erected elements and subsequently secured thereto edge to edge or are hoisted into their desired position individually for joining end to end and side to side with previously erected elements.
Both methods of construction are labour intensive and expensive.
Previously proposed buildings of this kind have not proven popular from either a commercial or manufacturing aspect. This appears due principally to high costs involved in formation and transportation of thin sheet metal elements of this kind and to handling difficulties and other constructional problems associated with such elements. Hence it is preferred that the formation of the building elements takes place at the site of the building to be erected. However, it has been found that conventional apparatus requires very long forming lines with a multiplicity of sets of forming rollers and as such have been somewhat impractical.
To address these problems the present inventor has previously proposed in Australian Patent application no. 48883/90 a method of erecting such buildings and apparatus for forming building elements of the above kind. Although the proposal goes a long way towards providing an effective and efficient solution to these problems it has been found that the proposed apparatus does not have sufficient operational flexibility to provide for building spans exceeding 20 meters. Additionally said apparatus is not sufficiently operationally flexible to provide adjustment of radius of curvature of the elements during operation and/or without considerable rearrangement and realignment of equipment and time loss.
An object of the present invention is to provide a process and apparatus which addresses one or more problems and deficiencies identified above or later in the specification.